Engine operated hot-air heater with engine demounting means



J. H. LESLIE, 1!. ET AL ENGINE OPERATED HOT AIR HEATER Oct. 19 .1948.

WITH ENGINE DEMOUNTING MEANS 5 Sheets-Sheet 1 std/1,04

Film; Dec. 8. 1943 NNY J. H. LESLIE, 11, ET AL 2,451,623

Oct. 19 1948.-

ENGINE OPERATED BOT AIR HEATER WITH ENGINE DEIOUNTING IIEANS 5Sheets-Sheet 2 Filed Dec. 8, 1943 L100 /06 402 I04 )1, 2 M 0 W ata Oct.'19 1948. J, su 11, r 2,451,623 I ENGINE OPERATED nor AIR HEATER WITHENGINE DENOUNIING MEANS Filed Dpc. 8, 1943 Oct. 19 1948. J. H. LESLIEJI,ETA-L 2,451,623

ENGINE OPERATED HOT AIR HEATER WITH ENGINE DEHOUNTING MEANS 5Sheets-Sheet 4 Filed Dec. 8. 1943 J. H. LESLIEI IL ETAL ENGINE OPERATEDno! AIR 112mm WITH ENGINE DEIIOUNTING MEANS 5 Sheets-Sheet 5 Filed Dec.8. 1943 WM Elk-1 1 lllll -I m Patented Oct. 19, 1948 a ENGINE OPERATEDHOT-AIR HEATER WITH ENGINE DEMOUNTING MEANS John H. Leslie, II,Winnetka, and George A.

Crosby, Park Ridge, 111., asslgnors to Stewart- WarnerCorporatiom'Chicago, 111., a corporation of Virginia I ApplicationDecember 8, 1943, Serial No. 513,368

7 Claims. (01. 126-110) Ourlnvention relates generally to heaters, andmore particularly to portable heaters usable at air fields and inmilitary operations to supply air at a high volumetric rate and at hightemperature to heat the engines and other parts of aircraft, to thaw outvehicles, and for similar purposes.

In the operation of air bases in northern latitudes, particularly inwinter, great difliculty has been experienced in conditioning aircraftfor take-off due tothe fact that the engines and 'other parts of theaircraft become literally ,frozen, that is, the oil congeals and themetal parts contract to such extent that it is substantially impossibleto start the engines. It has been found necessary to provide some meansfor at least partially enclosing the engines and to supply heated airthereto.

At very low temperatures, it is essential that the heating means becapable of supplying heat at a high rate, and since there is alimitation upon the maximum permissible temperature of the heating air,it is essential that the heated air be supplied at a high volumetricrate.'. The heating apparatus of our invention is particularly designedfor this purpose, and is capable of supplying large quantities of heatcarried by air at a reasonably high temperature and at a high volumetricrate.

In apparatus of this type used in the past, difliculty has frequentlybeen experienced in maintaining the heating apparatus in operation,since the apparatus includes an internal combustion engine whichlikewise presents starting difliculties in cold weather. Furthermore,such internal combustion engines, usually of the single cylinder typeare subject to failures in operation and occasionally require servicing.In the past, such servicing was rendered difficult by the position ofthe engine in the assembly and by the numerous connections between theengine and other parts of the apparatus which had to be severed prior toremoval of the engine for servicing.

In the apparatus of our invention, this difllcuity is overcome by makingthe engine readily detachable from the unit 'by simple operations, sothat it is feasible, if an engine of one unit fails to operate properly,to remove the engine therefrom and substitute a spare engine in afewminutes time, thus making it possible to continue use of the heater unitwhile the engine is being repaired or serviced.

A further object is to provide an improved heater unit assembly havingan internal combus- 2' v tion engine for driving a blower, and in whichthe internal combustion engine with the rotor of the blower may readilybe removed from the unit for replacement or servicing.

Other objects will appear from .the following description, referencebeing had to the accompanying drawings, in which Fig. 1 is a generallyside elevational view of the complete heater unit, portions of theexternal casing being broken away to show internal parts;

Fig. 2 is a fragmentary sectional view taken on the line 2--2 of Fig. 1,showing a detachable fuel line connection for the engine; I

Fig. 3 is a fragmentary sectional view taken on the line 3-3 of Fig. 1,showing the detachable fuel line connection for supplying fuel to theheater; I

- Fig.4 is a transverse sectional view taken on the line l| of Fig. 1;

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 4, and showinga detail of the chassis construction;

Fig. 6 is a transverse sectional view taken on the line 6-6 of Fig. 4,and showing particularly the blower casing; I

7 is a sectional view taken on the line 1-4 of Fig. 6;

Fig. 8 is a perspective view of the heater unit showing the engine,blower rotor, and rotor casing cover removed therefrom;

Fig. 9 is a sectional view of a modified toggle clamping means forsecuring the engine in the heater unit; and

Fig. 10 is a sectional view taken on the line llll0 of Fig. 9.

GENERAL DESCRIPTION In general, the portable. heater unit of ourinvention comprisesa welded tubular frame 30, the lower portion of whichis enclosed by a housing sheet 32 which is shaped in the manner of atoboggan or sled, so as to enable the unit to be pulled on snow, ice, orsand, or any-terrain over which the unit could not be efllcientlytrundled on its wheels. Formed as a part of the tubular welded frame 30,is a handle 34. An engine cover housing 36 is hinged to the lower casing32 by means of a hinge 38 the leaves of which may be weldedrespectivelyto the cover 36 and casing 32.

An internal combustion engine 40 is detacha'bly secured to the chassisframe 30 by means hereinafter to be described in greater detail, the

engine operating to drive a blower 42 having a rotor 44 (Fig. 4). Theblower supplies air to be heated, as well as air for combustion, to aheater accuses 3 48, the heated air from which is conveyed throughflexible ducts 48 to the space to be heated. A fuel tank 58 is securedto the chassis frame beneath the heater 48 and the space beneath thefuel tank 58 forms a. magazine for storage of the ducts 48 when theheater is not in use.

A pair of wheels 84 are individually spring.

mounted and are arranged to be moved from their lowered to a raisedposition by means of a handle 1 58 and a suitable intermediateoperatingmechanism.

Engine and blower construction and mounting As best shown in Figs. 4 to7, a cross channel 58 is welded to the tubular frame 38 and serves inpart as a support for a pair of engine supporting channels 88 (Figs. 4and 5) the other ends of these channels being supported by a reinforcingplate 82 which is'welded to the housing 82 and has a ledge portion 84extending through a suitable aperture in the housing 82. The channelmembers 88 have dowel headed pins 88 secured therein,

the upwardly projecting heads of these pins being conformed forreception in sockets 88 formed in the base flange 18 of a crank casecasting 12 forming part of the engine 48.

The flywheel housing 14 (Fig. 4) of the engine rests upon a resilientlymounted pad I8 to preclude the possibility of vibration and rattling.The engine 48 isheld in position over the heads of studs 98.

' The engine toggle clamping mechanism is shown in Fig. 4 in clampedposition, in which the vided with. a shutoff cock I22 'into which isthreaded a female detachable coupling I24, the.

latter being clamped to the male fitting I28 in the manner previouslydescribed with reference to Fig. 2. The male coupling element I28 isconnected by a. conduit I28 with a fuel jet nozzle.

The engine is preferably provided with magneto type ignition. A shieldedconductor I32 (Fig. 8) leads to a spark plug I84 forming part of theheater, the conductor being detachably secured to the spark plug by aneasily operable coupling nutl38. The engine 48 may be of conventionalconstruction and equipped with the usual appurtenances and accessories,such as an exhaust pipe I88, terminating in a muiiler I48.

An extension I42 (Figs. 4, 6 and 7) of the engine crank shaft has thehub I44 of the blower rotor 44 keyed thereto so as to normally beremoved with the engine, as indicated in Fig. 8. To permit such removal,the inner side wall I48 of the casing of the blower 42 has an openingI48 of suflicient size readily to permit passage of the rotor 44. Theopening I48 is surrounded by' a flange I58 which by interengagement witha cross piece ofthe ball has swung past dead center position, and inwhich the downwardly extending arms of the bail l8 a-but against stopears 92 projecting from the cylinder head. The ball i8 is preferably asteel rod which, due to its-shape, has suilicient elasticity to permitthe cross piece thereof to swing past dead center and to exert alarge-clamping force, holding the engine firmly against its supportingchannels 88. The engine has a fuel pump 94 (Fig. 1) driven thereby, thisfuel pump drawing liquid fuel, such as gasoline, from the fuel tank 58through a flexible hose lit. The hose 88 is connected to the fuel tank58 through a stop cook 98 and is detachably connected to a goosenecktube I88 by means of a detachable coupling connection I82. This couplingconnection I82 is shown in detail in Fig. 2, and comprises a femaleelement I8 which is suitably connected to the hose '98, and a maleelemen 988 which is connected to the tube I88. The coupling elementsI84, I88 have complementary conical seating surfaces I85, Illi, whilethe element 588 has a protecting flange I88. A yoke III! is pivoted tothe element I88 and has a thumb screw M2, the end of which is cooperablewith the element l84 to force the elements I84 and I88 together andefiect a fuel tight seal at the interengaging conical seating surfacesI85,

- The outlet of the fuel pump 94 has a conduit I I4 connected thereto,this conduit being provided with a T H8 from which a branch conduit II8leads to the float bowl I28 of the engine carburetor. The conduit Ii4beyond the T HE is progrooved bead I54 formed around the periphery of acover I58, locates the latter in position.

The cover I58 has a. resilient locking bar I88 pivotally secured to thecenter thereof, the bar being normally held from bending by a pair ofkeepers I82 welded to the cover I58. in order to clamp the cover I58 inposition, the bar I88 is swung counterclockwise from its dotted line toits full line position in Fig. 6, so as to cause its engagement beneathkeeper brackets I84which are welded to the blower housing shroud I48.

In order to remove the engine from the heater unit, the hinged cover 88is swung upwardly to the position in which it is shown in Fig. 8,resting against the handle 34. The detachable coupling connections forthe fuel line and spark plug are disconnected. The clamping bail 18 maythen be pulled outwardly (to the left, Fig. 4) through its dead centerposition. Then upon removal of the cover I58 from the blower casing I48,the engine may be raised and moved slightly to the left (Fig. 1),whereupon the rotor 44 of the blower will be brought into alignment withthe openin I 48 in the blower shroud and the engine may then be shiftedsidewardly (to the left, Fig. 4) to remove it completely from the heaterunit. The engine may, of course, be replaced by performing the abovedescribed operation in reverse order.

It will be noted from Fig. 8 that the hinged cover 38 is provided with ascreened opening I18 which, when the cover is in lowered position, isnear the blower inlet opening I12 to screen the air drawn into theblower.

Modified engine clamping mechanism pivotally connected to the brackets358 and has its cross piece 358 embraced by a bearing yoke 358, thelatter being secured to' a togglebracket 388. This bracket 388 isgenerally inverted U-shaped, and has a pair of sidewardly extend-' ingarms 382 provided with sockets on their lower faces for V engagementwith acorn nuts 384 threaded over the ends of cylinder head studs.

oppositely extending arms 383 engage of cylinder head studs 366. As willbe clearly apparent from Fig. 9, the axis of the cross piece 356 of thebail must pass through a dead center position in moving to and fromlooking position. In swinging the bail 354 into locking position, thesockets in the arms 35! are first engaged with the acorn nuts .354 andthe bail is then pushed to the right (Fig. 9) through its dead centerposition, the member 350 acting in the manner of a toggle, while thearms of the bail 354 spring sufiiciently to permit such movement throughdead center position. Upon passing dead center position, the togglemember 360 will be swung into position to cause its arms 353 to engagethe studs 365. When in this position, the bail 354 will be substantiallyflexed from its normal shape, and the bail will therefore exert asubstantial downward force, tending to hold the engine in place.

the ends Operation The apparatus of the invention is, as previouslyindicated, adapted for use at airports and landing fields, in preheatingairplane engines and cabins prior to take-ofl. It of course has manyother uses in thawing out various kinds of machines and equipment, andalso for providing heat to various structures requiring heat.

Having trundled or pulled the apparatus to the equipment or structuredesired to beheated, the operator, checking to see that all the 'fuelvalves are open, will crank the engine, whereupon the fuel pump thereofwill'force the fuel to the nozzle I30 in a fine atomized spray. Thespark plug I34 is preferably connected in series with the engine sparkplug, so that each time the engine fires a spark will be produced at thespark plug I34 to ignite the atomized fuel and air mixture. Having beenignited, combustion will ordinarily continue uninterruptedly. However,should the flame become extinguished, the spark plug, operatingsubstantially, continuously, will immediately cause reignition.

The ventilating air flowing through the heat exchanger is dischargedthrough one or both of the flexible heated air conduits 48 which may beconnected to supply air through an aperture in the cowl or nacelle ofthe airplane engine, or may be secured to the structure of any otherpart to which heat is to b delivered.

The blower operates to force the ventilating air into the heat exchangerat a relatively high velocity, so that not only is the heat transferefiiciently accomplished, but the flow through the flexible conduits 48is maintained at a high velocity and the air discharged from the nozzlesat the end thereof will have suflicient kinetic energy to flow betweenand around machine parts and rapidly heat the latter to the desiredtemperature.

Whenever it is found desirable or necessary to remove the engine, thiscan be accomplished in a few seconds merely by disconnecting the fuelline coupling connections I02 and I 24, disconnecting conductor I32 fromthe spark plug I34, and swinging the bail 18 to engine releasingposition. Thereafter, upon removing the blower cover plate I56, theengine may be raised from its locating dowel pins 65 sufficiently tobring the biower' rotor 44 in alignment with the opening I48, whereuponthe engine may be moved sidewardly (toward the left, Fig. 4) and thuseasily removed from the assembly. The fact that the hood '36 may beswung clear, as shownin Fig.8, simplifies the operation of removing theengine. ,An engine in proper operating condition, together with itsblower rotor 44, maythen quickly and easily be secured in operatingposition in the apparatus by performing the above described opcrationsin reverse order.

The storage space for the flexible ducts 48 is provided by the spacebetween the fuel tank 50 and the bottom wall 32, thus avoiding thenecessity for providing additional housings or casings for the storageof these ducts.

While we have shown and described particular embodiments of ourinvention, it will be apparent that numerous variations andmodifications thereof may be made without departing from-the underlyingprinciples of the invention. We therefore desire, by the followingclaims, to include within the scopeof our invention, all such variationsand modifications by which substantially the results of our inventionmay be obtained through the use of substantially the same or equivalentmeans.

'We claim:

1 In a unit heater of the type employing a hermetically sealedcombustion unit and an engine operated blower for supplying combustionand ventilating air to said combustion unit, the combination of achassis having means cooperable with the base of the engine for locatingthe latter with respect to the chassis, a resilient bail having its armspivoted to the chassis adjacent thebase of the engine, and meanspivotally connected to the cross piece of said bail and engageable withparts at the top of the engine, said last named means including elementshaving, together with said bail, a toggle effect resiliently to clam theengine to the chassis.

2. In a unitheater of the type employing a hermetically sealedcombustion unit and an engine operated blower for supplying combustionand ventilating air to said combustion unit, the combination of achassis having dowel means 'cooperable with the engine for locating thelatter at the top of the engine, said last named means combustion enginehaving a drive shaft secured to the rotor of said blower, means forclamping 1 said engine and blower rotor in position whereby said rotorof the blower is in operative location within said casing, a removablepanel forming part of said blower casing and adapted when removed topermit removal of said engine with the rotor of the blower attachedthereto, a source of fuel for said combustion and heat exchange meansand said engine, a fuel pump operated by said engine, andquick-detachable conduit connections between said source and said fuelpump and between said fuel pump and said combustion and heat exchangemeans.

4. In a portable self-contained heating unit ,having combustion and heatexchange means, a

blower comprising a rotor and casing for supplying combustion andventilating air to said combustion and, heat exchange means, an internalcombustion engine having a drive shaft secured to the rotor of saidblower, means for clamping said engine and blower rotor in positionwhereby said rotor is in operative location withinsaid casing, and aremovable panel forming part of said blower casing and adapted whenremoved to permit removal of said engine with the rotor of the blowerattached thereto.

5. In a portable self-contained heating unit having combustion and heatexchange means, a blower comprising a rotor and casing for supplyingventilating air to said heat exchange means, an internal combustionengine having a drive shaft secured to the rotor of said blower, meansfor clamping said engine and blower rotor in position whereby said rotoris in operative location within said casing, and a removable panelforming part of said blower casing and adapted when removed to permitremoval of said engine with the rotor of the blower attached thereto.

6. In a portable self-contained heating unit having combustion and heatexchange means, an

engine and a blower operated thereby for supplying ventilating air tosaid heat exchange means,

a chassis having means co-operable with the base of--the engineforlocating the latter with respect to the chassis, a resilient bail havingits arms pivoted to the chassis adjacent the base of the engine, andover-center toggle means co-operating with said ball and the upperportion of said engine for causing said ball when said over-centertoggle mechanism is in one position resiliently to clamp the engine tothe chassis.

7. In a unit heater of the type described the combination called for inclaim 6 in which the 5 engine is an internal combustion engine having 2.drive shaft secured to the rotor or said blower, a casing for saidrotor, a removable panel forming part of said blower casing and adaptedwhen removed to permit removal of said engine with m the rotor of theblower attached thereto.

, s I JOHN H. LESLIE, 11. GEORGE A. CROSBY.

REFERENCES CITED 1:; The following references are of record in the fileof this patent:

UNITED STATES PATENTS Number Name Date 20 D. 135,577 Holthouse Apr. 27,1943 1,519,673 Doble Dec. 16, 1924 1,779,129 Heckman ..i 1 Oct. 21, 19302,106,530 Kelly Jan. 25, 1938 2,235,967 Sunday Mar. 25, 1942 252,295,177 King Sept. 8, ,1942 2,310,274 Beckett Feb. 9, 1943 2,355,631Carter Aug. 15,1944 2,405,427 Holthouse Aug. 6, 1946 3G FOREIGN PATENTSNumber Country Date Netherlands Jan. 15, 1937'

